Mechanism illustrating steam-engine valve-motions of different constructions.



No. 718,193. EATENTEE JAN.13, 1903.

E; E. coLVIN. MECHANISM ILLUsTEAT-ING lSTEAM ENGINE VALVE MOTIoNs- 0E DIFFERENT GONSTRUGTIONS.

APPLICATION FILED NOV. 1, 1902.

Tu: Nanms Erzns co., mom-uwe. wAsHmaTnN. n. c.

UNITED STATES PATENT OFFICE.

HENRY F. CO'LVIN, OF PHILADELPHIA, PENNSYLVANIA.

` MECHANISM ILLUSTRATING STEAM-ENGINE VALVE-MOTIONS 0F DIFFERENT CONSTRUPCTIONS.

SPECIFICATION forming part of Letters Patent No. 718,193, dated January 13, 1903.

. Application filed November 1, 1902. Serial No. 129,660. iNo model.)

This invention relates to mechanism for the I diifusion of knowledge in regard to steam-engine valves and their operative mechanism.

The construction is of a size to be readily portable, while exhibiting f ull-size valves and valve-faces, with full-size ports and Valve travel up to the limit in use. Its various parts being compact, its cost will be so slight as to permit its introduction generally into club and lodge rooms of mechanical societies, schools, and scientific associations, as well as to private students interested in steam-engine construction and operation. It shows in full size the control of the induction and eduction ports by the valve, the effect of lap and lead as produced by different valve motions and travel and as influenced by eccentrics or other prime movers when in advance of the crank or following it, the position of the piston and cross-head at the time of cut olf and release, with increase r decrease of lead or uniform lead throughall points of cut-off, the amount of compression due to the time of release or opening of the induction-ports.

The mechanism is designed for and adapted to illustrate the working of the valve of any form or proportion of engine and with either slide or piston valves.

The accompanying drawings, in which similar parts are referred to by similar reference characters, illustrate`the invention, and in which- Figure 1 is a front elevation view showing the valve and valve-seats with their ports and openings. Fig. 2 is a vertical central section on line :n oc, Fig. 1. Fig. 3 is a rear elevation view showing the crank and motion-plate with its slots for different forms of valve-moving mechanisms. Fig. 4 is a longitudinal central section on line o fu, Fig. 3.

A plate l is the foundation'for the working parts, and it may be either of rectangular form, as shown, or, if desired, of oval or circular form, and it is supported by standards 2 3,as shown, or other suitable form, removably rivets 8 or other suitable means is an annular f disk 9 in front of plate l and a disk-crank 10 at the back of the'plate. Disk 9 and crank l0 are ofgreater diameter than ring 7 and overlap plate l. This secures them sidewise outside of y the plate, where they are free to turn Without friction against the plate, the crank havinga handle 1l for such purpose. In front of disk 9 is a plate l2, slightly shorter than plate 1 and secured forreciprocating movement byguides 13 14 with cover-plates l5 16, which are also clips for securing the removable valve-seat cards, which are hereinafter described. Plate l2 has attached thereto one end of the long member 17 of a parallel-motion connectingrod in a lslot 18, and at the other end it is attached to a motion-plate 19 at the back of crank 10, the motion-plate being secured by thumb-nuts and screws 20, passing through slots 21, to permit the adjustment of the plate. A short member 22 of the connectingrodis attached at one end to member 17, and at its opposite end it is secured to the reciprocating motion-plate 12 at its center. The members 17 22 form a parallel motion. In plate 19 is a central vertical straight slot 23, representing and used for valve-motions having a uniformlead, and at each side are reversely- Acurved slots 24, representing and used for Valve-m otions having an'increasing lead, and 25, representing and used for valve-motions having a decreasing' lead. Scales 26 are shown on plate 19 for the convenience of accurate adjustments of the plate either Way from zero-lines 28,"equiv'alent to the angularity at which the eccentrics or other prime movers are set to Work ed the lap and lead at the commencement of the stroke, lines 29, being the centers of slot 24, coinciding with lines 28, and lines 30, being the centers of slot 25, coinciding with lines 28. 'Upon the reciprocating motion-plate 12 is a card representing a common D-valve 3l, removably secured by clip 32, which in turn is held by screw and thumb-nut 33. Disk 9 is graduated in inches of its rotary movement corresponding to the inches of reciprocating move- IOO ment of a piston and cross-head of the same stroke, but commencing at right angles to the cranks dead-centers,and above and below the disk, upon plate 1, are lines 34, representing the dead-centers ot' the crank and the commencementand ending of each stroke. This arrangement facilitates the reading of the piston travel, as the disk divisions and Iigures are always in sight when approaching lines 34. Plate 13 supports a removable card 35, representing a valve-seat, and is secured by clips 15. For slide-valves in which the steam passes through the valve and also for piston valves an additional card may be placed on plate 14 and secured by clips 16. Plate 19 has horizontal graduating lines 36, representing an eccentrics throw or its concentric path or representing the movement of other prime movers where eccentrics are not used. As illustrated, the rod 17 being secured in slot 23 of motion-plate 19 the rotation of crank l0 will move valve 31 forward and back each way an amount equal to twice -the distance at which rod 17 is secured in slot 23 beyond its center. When plate 19 is set over to represent the corresponding angular position of the eccentrics or the prime mover, due to lap and lead, the mechanism will then correctly control the valve to indicate its action in connection with the steam and exhaust ports and the piston and crank movements, and the same will be true when the rod 17 islattached in slot 24 or slot 25.

I claim-- 1. In a mechanism of the character described, a foundationplate, a disk graduated to indicate circular movements equivalent to lhesame amountof reciprocatingmovements, and placed at one side of the plate, and a disk-crank at the opposite side of the plate, the disk and crank being secured together and supported by the plate for free rotary movement.

2. In a mechanism of the character described,afoundation-plate, an aperture therein, an annular ring in the aperture, au annular disk secured at one edge of the ring, a diskcrank secured at the opposite edge, the disk and crank extending outward beyond the ring and clear of the plate; lines upon the plate at right angles to the cranks deadcenters, graduations upon the annular disk spaced to indicatea cranks rotary movement equivalent in amounts or distances to the re ciprocating movements of a piston having the same stroke, the commencement and ending of the crank and piston stroke as indicated on the disk, coinciding with the lines on the plate aforesaid.

3. In a mechanism of the character described, a graduated disk and a crank snpported for rotary,movement, a plate opposite thereto and guided for reciprocating movement, and means to connect the crank to the plate for its movement.

4:. In a mechanism of the character described, a disk and a crank, means for their connection and support for rotary movement, a plate guided for reciprocating movement, means for its driving bythe crank, and means to removably secure represen tations of valves thereon.

i Y 5. In a mechanism of the character described, a disk and a crank, means for their connection and support for rotary movement, an oppositely-supported plate guided for reciprocating movement, means for its driving by the crank, means to removably secure representations of valves thereon, and means to removably secure above and below the Valve representations of valve-seats.

6. In a mechanism for the purpose described, a rotatable disk and crank secured for unison in movement, a plate guided for reciprocating movement, a motion-plate adjustably secured to the crank, means to connect the motion-plate to the reciprocating moving plate in manner to regulate the amount of reciprocating movement.

7. In a mechanism such as described, a crank and a disk connected and supported for rotary movement, a plate guided for reciprocating movement, a motion-plate secured to the crank for movement toward or from the cranks arm, graduations for the amount of movement, a straight slot in the plate at a right angle to the crank, and a parallel-motion connecting-rod comprising two members, the longer one yieldingly connected to the reciprocating motion-plate at one end and to the slot aforesaid in the motionplate at its other end, and its shorter member connected at one end to the center of the reciprocating motion-plate, and to the longer member at the other end.

8. In a machine such as described, a crank and a disk united and supported for rotary movement, a reciprocating movement-plate, a motion-plate adjustably secured to the crank, a central straight slot therein, and at each side thereof reversely-curved slots, a parallel-motion connecting-rod comprising two members, one of said members being yieldingly connected to the reciprocating movement-plate at one end, and adapted to engage one of the aforesaid slots at its opposite end, the other member being connected to the reciprocatingmovement-plate at its center, at one end, and to the first-mentioned member at its opposite end, and a graduated scale to indicate the position of the connecting-rod in the slots.

9. In a mechanism as set forth, a rotatable crank and disk, a reciprocating plate, means for their connection and operation as set forth, representations of a valve and its seats, and supports for the apparatus detachably secured, to facilitate portability.

In testimony whereof I affix my signature in presence of two witnesses.

HENRY F. COLVIN.

Witnesses:

RANsoM C. WRIGHT, WILLIAM C. STOEVER.

IIO 

